Diode. The diode acts as a gate that only lets current flow one way. Place up to five diodes in the simulation window. With the Select tool, you can move and rotate diodes, and wire them to other objects. You attach wires to the diode's two nodes, which are indicated by the yellow rectangles in Figures 1 and 2.

Fig. 1 Fig. 2

The diode is all or nothing. Either it lets no charge past its gate (Figure 3 below), or it lets a current of any size go through (Figures 4 and 5). The figures below also illustrate how a diode must be wired to let current pass through.

Fig. 3

Fig. 4

Fig. 5

In the diode's Properties Box, you can turn the light on when current runs through the diode. Default is to have the light turn on.